CAMBRIDGE, Mass., March 24, 2016 /PRNewswire/ -- Merrimack Pharmaceuticals, Inc. (Nasdaq: MACK) today announced the National Comprehensive Cancer Network (NCCN) has included ONIVYDE® (irinotecan liposome injection) in combination with fluorouracil (5-FU) and leucovorin in its 2016 Clinical Practice Guidelines in Oncology for pancreatic adenocarcinoma. The new guidelines recognize the ONIVYDE regimen as a category 1 second-line therapy for patients with metastatic adenocarcinoma of the pancreas who have previously been treated with gemcitabine-based therapy. A category 1 classification represents the highest level of evidence and uniform NCCN consensus that the intervention is appropriate. The new guidelines are published on www.nccn.org .

"The addition of the ONIVYDE regimen to the 2016 NCCN guidelines further validates the importance of this treatment option for patients battling metastatic pancreatic cancer," said Edward J. Stewart, Head of Commercial at Merrimack. "ONIVYDE is the only FDA approved therapy available to patients whose disease has progressed after gemcitabine-based therapy and, more importantly, it addresses a critical unmet need in a patient population with very limited options. We believe these guidelines will further support the adoption of the ONIVYDE regimen as a standard-of-care in metastatic pancreatic cancer."

Pancreatic cancer is a rare and deadly disease. Each year approximately 53,000 patients are diagnosed with pancreatic cancer in the United States with only 7% surviving five years or longer1. The NCCN's recommendation was based on a review by a multidisciplinary panel of experts from NCCN member institutions and supported by data from the NAPOLI-1 study, published in The Lancet in 2015, and the U.S. Food and Drug Administration (FDA) approval of the ONIVYDE regimen. NAPOLI-1 was a randomized, open label Phase 3 study in patients with metastatic adenocarcinoma of the pancreas who received prior gemcitabine-based therapy, and was the largest Phase 3 study in this setting to date. Patients were enrolled at 76 sites in North America, South America, Europe, Asia and Oceania.

NCCN is an alliance of 26 world-class cancer centers dedicated to the development of treatment guidelines for most cancers and to research that will ultimately improve the quality of patient care and outcomes. The NCCN guidelines are widely recognized as the standard of clinical practice in oncology and provide evidence-based treatment recommendations to assist key stakeholders, including physicians, patients and payers, in directing cancer patient care.

About ONIVYDE® [pronounced \ 'on - īh – vide \]

ONIVYDE® (irinotecan liposome injection), also known as MM-398 or "nal-IRI," is a novel encapsulation of irinotecan in a liposomal formulation. The activated form of irinotecan is SN-38, which functions by inhibiting topoisomerase I (an essential enzyme involved in DNA transcription and replication) and promoting cell death. ONIVYDE was recently approved by the U.S. Food and Drug Administration in combination with fluorouracil and leucovorin for the treatment of patients with metastatic adenocarcinoma of the pancreas after disease progression following gemcitabine-based therapy. For full prescribing information, including Boxed WARNING, please visit www.ONIVYDE.com.

About Merrimack

Merrimack is a fully integrated biopharmaceutical company that views cancer as a complex engineering challenge. Through systems biology, which brings together the fields of biology, computing and engineering, Merrimack aims to decrease uncertainty in drug development and clinical validation, and move discovery efforts beyond trial and error. Such an approach has the potential to make individualized treatment of patients a reality. Merrimack's first commercial product, ONIVYDE® (irinotecan liposome injection), was approved by the U.S. FDA on October 22, 2015. With four additional candidates in clinical studies, several in preclinical development and multiple biomarkers designed to support patient selection, Merrimack is building one of the most robust oncology pipelines in the industry. For more information, please visit Merrimack's website at www.merrimack.com or connect on Twitter at @MerrimackPharma.

Forward-Looking Statements

To the extent that statements contained in this press release are not descriptions of historical facts, they are forward-looking statements reflecting the current beliefs and expectations of management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements include any statements about Merrimack's strategy, future operations, future financial position, future revenues and future expectations and plans and prospects for Merrimack, and any other statements containing the words "anticipate," "believe," "estimate," "expect," "intend," "may," "plan," "predict," "project," "target," "potential," "will," "would," "could," "should," "continue," and similar expressions. In this press release, Merrimack's forward-looking statements include, among others, statements about the potential adoption of the ONIVYDE regimen as a standard-of-care. Such forward-looking statements involve substantial risks and uncertainties that could cause Merrimack's clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, the uncertainties inherent in the initiation of future clinical trials, availability of data from ongoing clinical trials, expectations for regulatory approvals, development progress of Merrimack's companion diagnostics, availability of funding sufficient for Merrimack's foreseeable and unforeseeable operating expenses and capital expenditure requirements, and other matters that could affect the availability or commercial potential of Merrimack's products, product candidates or companion diagnostics. Merrimack undertakes no obligation to update or revise any forward-looking statements. Forward-looking statements should not be relied upon as representing Merrimack's views as of any date subsequent to the date hereof. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to Merrimack's business in general, see the "Risk Factors" section of Merrimack's Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on February 26, 2016 and other reports Merrimack files with the SEC.